The present invention relates to sugar cane harvesters and more particularly relates to steering arrangements for such harvesters.
The steering arrangement on a typical front wheel steered, rubber tired sugar cane chopper harvester includes steerable wheels mounted to axles supported for pivoting about respective upright pivot structures located outboard of transversely spaced, fore-and-aft extending main frame members. A pair of crop dividers are respectively mounted to the main frame ahead of the pair of steerable wheels. In order to avoid interference with the frame members during steering operation, a large space is provided between each pivot axis and the adjacent frame member.
A first disadvantage of the known steering geometry is that, in order to reposition the harvester on the field headland for entering a new row of cane to be harvested after exiting a row just harvested, an operator must not only turn the steerable wheels but also must do a series of machine reversals in order to enter the new row without damaging the cane. This same sequence may also be repeated at the end of the field when exiting the row and turning onto the headland. In this case, the rear of the machine may be backed into the uncut field, knocking cane down and damaging the crop. With short rows and narrow headlands, the time spent maneuvering existing machines can be longer than the time spent harvesting.
A second disadvantage of the known steering geometry is that of restricting the width of the machine throat for accepting crop for being separated from the ground by a pair of counter rotating base cutters located between the main frame members. This restricted feed throat causes a problem referred to as glut/starve feeding when cutting heavily lodged, green cane. The problem begins when stalks of cane bridge the throat and momentarily starve the flow of cane into the machine. When enough cane accumulates to either bend or break the bridged stalks, a glut of cane is fed into the machine. If the cane processing elements located past the throat have enough capacity, the glut of cane will go through the machine, although the quality of the cane exiting the machine will be reduced. If the glut is too large, a choke will occur which will result in machine stoppage to clear it.
According to the present invention, there is provided an improved steering arrangement for a rubber tired chopper cane harvester.
An object of the invention is to provide a steering arrangement which results in a geometry defining an increased throat width for receiving crop.
A more specific object of the invention is to provide a steering arrangement whereby the steerable wheels are mounted for movement together with respective frame sections that are mounted for pivoting about upright axes, whereby the wheels may be mounted close to the frame sections without any possibility of interference, thereby permitting the frame sections to be spaced from each other so as to increase the throat width for receiving crop.
Another specific object is to provide a steering arrangement, as defined in the immediately preceding object, wherein in addition to the steerable wheels, the crop dividers are also respectively coupled for pivoting with the frame sections.
Still another object of the invention is to provide a steering arrangement wherein the topper mechanism is steered in response to steering the vehicle.